1. Field of the Invention
The present invention relates to a stirling engine and more particularly to a stirling engine with a controllable output.
2. Description of the Related Art
In recent years, stirling engines which have an excellent theoretical thermal efficiency attract attention as an external combustion engine which collects exhaust heat from an internal combustion engine mounted on a vehicle such as an automobile, a bus, and a truck, as well as exhaust heat from factories.
Japanese Patent Application Laid-Open No. S64-342 discloses an output control apparatus for a stirling engine which includes a connection tube that connects a working space and a crankcase and an accumulator.
Control of the output of the stirling engine is desired. In particular, it is desirable to allow more simplified control of the output of the stirling engine.